Table 3. Clinical symptoms and pre-existing diseases in study participants.

Symptom/pre-existing disease		Seasonal influenza A virusA+B−, pdm−(n = 46)	Seasonal influenza B virusA−B+, pdm−(n = 19)	H1N1pdmA+B−, pdm+(n = 196)	Possible H1N1pdmA−B−, pdm+(n = 12)	Positive seasonalA/B and H1N1pdm(n = 273)	NegativeA−B−, pdm−(n = 269)
Fever		44 (95.7%)	18 (94.7%)	196 (100%)	12 (100%)	270 (98.9%)	264 (98.1%)
Upper respiratoryinflammation		33 (71.7%)	8 (42.1%)	99 (50.5%)	5 (41.7%)	145 (53.1%)	119 (44.2%)
Lower respiratory	Pneumonia	2 (4.3%)	1 (5.3%)	20 (10.2%)	1 (8.3%)	24 (8.8%)	17 (6.3%)
inflammation	Asthma	0 (0%)	0 (0%)	1 (0.5%)	0 (0%)	1 (0.4%)	0 (0%)
Cough	Wet	15 (32.6%)	6 (31.6%)	57 (29.1%)	3 (25.0%)	81 (29.7%)	42 (15.6%)
	Dry	13 (28.3%)	4 (21.1%)	75 (38.3%)	4 (33.3%)	96 (35.2%)	35 (13.0%)
Arthritis		22 (47.8%)	5 (26.3%)	100 (51.0%)	5 (41.7%)	132 (48.4%)	117 (43.5%)
Muscular pain		11 (23.9%)	3 (15.8%)	58 (29.6%)	2 (16.7%)	74 (27.1%)	51 (19.0%)
Diarrhea		4 (8.7%)	1 (5.3%)	2 (1.0%)	0 (0%)	7 (2.6%)	13 (4.8%)
Vomiting or nausea		2 (4.3%)	1 (5.3%)	9 (4.6%)	1 (8.3%)	13 (4.8%)	16 (5.9%)
Malaise		6 (13.0%)	2 (10.5%)	17 (8.7%)	5 (41.7%)	30 (11.0%)	44 (16.4%)
Pharynx pain		1 (2.2%)	0 (0%)	9 (4.6%)	0 (0%)	10 (3.7%)	62 (23.0%)
Abdominal pain		1 (2.2%)	0 (0%)	2 (1.0%)	0 (0%)	3 (1.1%)	5 (1.9%)
Headache		3 (6.5%)	1 (5.3%)	24 (12.2%)	0 (0%)	28 (10.3%)	21 (7.8%)
Nasal discharge		1 (2.2%)	0 (0%)	11 (5.6%)	0 (0%)	12 (4.4%)	12 (4.5%)
Hypertension		0 (0%)	0 (0%)	2 (1.0%)	1 (8.3%)	3 (1.1%)	7 (2.6%)
Diabetes		0 (0%)	0 (0%)	1 (0.5%)	0 (0%)	1 (0.4%)	1 (0.4%)
Asthma		2 (4.3%)	0 (0%)	5 (2.6%)	0 (0%)	7 (2.6%)	2 (0.7%)
Renal disease		0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)	1 (0.4%)
Dialysis		0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)	0 (0%)
Allergy		0 (0%)	1 (5.3%)	3 (1.5%)	0 (0%)	4 (1.5%)	2 (0.7%)
Pregnancy		1 (2.2%)	0 (0%)	0 (0%)	0 (0%)	1 (0.4%)	0 (0%)